1. Field of the Invention
This invention relates to a fluid-cooled mount for an injector.
2. Description of Related Art
Injection of one fluid into another is a frequent operation applied in the chemical processing industry. In cases where the receiving fluid or processing environment are at elevated temperatures, the injection equipment is at risk of thermal damage. In some applications, objects may strike the injection equipment, thus leading to the possibility of impact damage. This is of particular importance in connection with injectors and equipment utilized in engine exhaust purification. That is, engine exhaust purification may involve a process whereby one or more liquid reagents are injected into a stream of hot engine exhaust. This reagent is typically employed in connection with lean NOx catalysts, SCR systems, or particulate filter systems. Since the exhaust gas is at an elevated temperature (200-600xc2x0 C.), the injector is subject to significant thermal load. This can lead to injector malfunction and thus system failure. Because of very strict federal DOT and EPA regulations and state statutes, it is imperative that such exhaust be capable of being purified on a reliable and effective basis without risk of damage or breakdown of the equipment.
Reagent injectors for engine exhaust purifiers are sometimes installed on trucks, buses and off-road vehicles. The environment on the exhaust pipe (under or behind the vehicle) can be hazardous for delicate components like injectors because of impacts from road debris such as rocks, metal shards, etc.
The basic principle of injecting fuel or an other reagent into an exhaust pipe has been known and practiced in the art since the early days of automobile catalytic converters and is described in, for example, U.S. Pat. Nos. 3,842,600 and 3,945,204.
U.S. Pat. Nos. 4,341,193; 4,436,071; 4,503,826; 4,539,962; 4,905,651; 5,280,774; and 5,605,042 disclose fuel injectors in which the fuel circulates through a chamber formed within the body of the injector and a part only of that fuel is dispensed from that chamber by passing from that chamber into the nozzle of the injector and opening of a valve in the nozzle of the injector.
U.S. Pat. No. 5,522,218 discloses a combustion exhaust purification system including an injector for injecting a NOx reducing fluid into the exhaust passage. The injector is cooled by the flow of engine cooling fluid through passages entirely within the injector mounting.
U.S. Pat. No. 5,915,626 discloses a fuel injector where the fuel is heated, and the magnetic coil of the injector valve consequently cooled, by passage of the fuel through the injector.
U.S. Pat. No. 6,279,603 discloses a fluid cooled injector for delivering a fluid into a hot gas stream, such as an exhaust gas stream, in which the fluid to be injected circulates through a chamber formed within the body of the injector and a portion of that fluid is dispensed from that chamber into the gas stream by opening of a valve in the chamber.
U.S. Pat. No. 6,481,641 discloses a fuel injector assembly having a heat exchanger for fuel preheating where the fuel to the injector passes through a preheater chamber surrounding the injector.
These and other documents cited in this application are incorporated into this application by reference.
In a first aspect, this invention is a fluid-cooled mount for an injector, the injector having a fluid inlet for receiving a fluid to be dispensed through the injector, a closed body, and a nozzle for dispensing the fluid, the mount comprising:
(a) a mounting block for receiving the injector, having an interior and an exterior and:
(i) an injector body receiving chamber and an injector nozzle receiving chamber within the interior of the block, contiguous with one another at a surface lying in the block, the injector body receiving chamber extending through a first exterior surface of the block and the injector nozzle receiving chamber extending through a second exterior surface of the block,
the injector body receiving chamber being configured to receive the body of the injector;
the injector nozzle receiving chamber being configured to receive the nozzle of the injector when the body of the injector is received in the injector body receiving chamber;
the fluid inlet of the injector lying exterior to the block when the body of the injector is received in the injector body receiving chamber,
(ii) a first seal configured to prevent fluid flow between the injector body receiving chamber and the exterior of the block when the injector is received in the block;
(iii) a second seal configured to prevent fluid flow between the injector body receiving chamber and the injector nozzle receiving chamber when the injector is received in the block;
(iv) a fluid inlet connecting the injector body receiving chamber to the exterior of the block;
(v) a fluid outlet connecting the injector body receiving chamber to the exterior of the block; and
(b) a manifold connecting the fluid inlet of the block to the fluid inlet of the injector.
In a second aspect, this invention is a fluid-cooled injector comprising the fluid-cooled mount of the first aspect of this invention with an injector received therein.
In a third aspect, this invention is a fluid-cooled injector system employing the fluid-cooled injector of the second aspect of this invention.
In a fourth aspect, this invention is a combustion exhaust purification system employing the fluid-cooled injector system of the third aspect of this invention.
In a fifth aspect, this invention is a method of dispensing a fluid using the fluid-cooled injector of the second aspect of this invention or the fluid-cooled injector system of the third aspect of this invention.
In a sixth aspect, this invention is a method of combustion exhaust purification by use of the combustion exhaust purification system of the fourth aspect of this invention.